title: Detection of capsule in strains of Clostridium difficile of varying virulence and toxigenicity.
abstract: Nine toxigenic and six non-toxigenic strains of Clostridium difficile, of varying virulence in the hamster model of antibiotic-associated colitis, were examined for the presence of a capsule. Antibody stabilisation of the capsule with heterologous and/or homologous antiserum fixed in glutaraldehyde, or direct fixation in glutaraldehyde/diamine, were used with added ruthenium red to stain the capsular glycocalyx. All strains possessed a capsule which was either loose-knit or compact, sometimes with attached globular masses. Better capsule preservation was achieved in some strains with glutaraldehyde/diamine/ruthenium red fixative than with homologous or heterologous antibody stabilisation. The possession of a capsule following in vitro growth does not appear to correlate with the virulence status of these strains of C. difficile.
authors.affiliation: Electron Microscopy Support, Clinical Research Centre, Harrow, Middlesex, U.K.
authors.forename: H A
authors.initials: HA
authors.lastname: Davies
authors.forename: S P
authors.initials: SP
authors.lastname: Borriello
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D016360:Clostridioides difficile / Q000276:immunology / Q000472:pathogenicity* / Q000648:ultrastructure; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology*; D008854:Microscopy, Electron; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D011817:Rabbits; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial